Function epoll_ctl [src]
Prototype
pub fn epoll_ctl(epfd: i32, op: u32, fd: i32, event: ?*system.epoll_event) EpollCtlError!void Parameters
epfd: i32op: u32fd: i32event: ?*system.epoll_event Possible Errors
op was EPOLL_CTL_ADD, and the supplied file descriptor fd is already registered with this epoll instance.
The target file fd does not support epoll. This error can occur if fd refers to, for example, a regular file or a directory.
op was EPOLL_CTL_MOD or EPOLL_CTL_DEL, and fd is not registered with this epoll instance.
fd refers to an epoll instance and this EPOLL_CTL_ADD operation would result in a circular loop of epoll instances monitoring one another.
There was insufficient memory to handle the requested op control operation.
The Operating System returned an undocumented error code.
This error is in theory not possible, but it would be better to handle this error than to invoke undefined behavior.
When this error code is observed, it usually means the Zig Standard Library needs a small patch to add the error code to the error set for the respective function.
The limit imposed by /proc/sys/fs/epoll/max_user_watches was encountered while trying to register (EPOLL_CTL_ADD) a new file descriptor on an epoll instance. See epoll(7) for further details.
Source
pub fn epoll_ctl(epfd: i32, op: u32, fd: i32, event: ?*system.epoll_event) EpollCtlError!void {
const rc = system.epoll_ctl(epfd, op, fd, event);
switch (errno(rc)) {
.SUCCESS => return,
else => |err| return unexpectedErrno(err),
.BADF => unreachable, // always a race condition if this happens
.EXIST => return error.FileDescriptorAlreadyPresentInSet,
.INVAL => unreachable,
.LOOP => return error.OperationCausesCircularLoop,
.NOENT => return error.FileDescriptorNotRegistered,
.NOMEM => return error.SystemResources,
.NOSPC => return error.UserResourceLimitReached,
.PERM => return error.FileDescriptorIncompatibleWithEpoll,
}
}